HELP PLS!!!

What version of ChemLab are you using?

I am using ChemLab version: 2.6





Trial One:

Initial Buret Volume: 50.0 mL

Volume of Potassium Permanganate added: 18.1



Trial Two:

Initial Buret Volume: 50.0 mL

Volume of Potassium Permanganate added: 18.8



Trial Three:

Initial Buret Volume: 50.0 mL

Volume of Potassium Permanganate added: 19.1



Average Volume of Potassium Permanganate (in litres) used. Be sure to show your work:


(0.0181 + 0.0188 + 0.0191) / 3 = 0.0187


Moles of
MnO−4



4
−

used

= 0.100 M x Average Volume of KMnO4

= 0.100 M x 0.0187 L

= 0.00187 Moles



Mass of iron(II)

= 5 x Mole Mass of iron(II) x Moles of
MnO−4


= 5 x 55.85 grams/mole x 0.00187 Moles

= 0.522



% of iron(II) in unknown

= (Mass of iron(II)/Mass of unknown) x 100%

= (0.522/1.00) * 100% = 52.2%



Summary:

Answer the following additional questions using this balanced equation:

8H++ MnO−4 + 5Fe2+ → Mn2+ + 4H2O +5Fe3+

Why did the solution in the beaker turn from yellow to pink (be sure to indicate the substance that is yellow and the substance that is violet from the Introduction)? What is the color of the Fe2+ in the sulfuric acid (the color in the flask at start)? What is the color is the Fe3+ (see introduction notes)? What is the color of the MnO4- (in the buret)? Mn2+ is colorless. Refer to the equation above. MnO4- is reacting with the Fe2+ to make Mn2+ and Fe3+. When all the Fe2+ has reacted you will just be adding MnO4-. Now what happens to the color? (All in one answer)